Erik Walden headbutts Delanie Walker after ripping his helmet off

Erik Walden was penalized during the second quarter of Thursday’s Indianapolis Colts-Tennessee Titans game for headbutting Delanie Walker. Walden and Walker were tangled up after Walker blocked Walden on a running play. A frustrated Walden ripped off Walker’s helmet, so Walker walked up to Walden. Walden responded by headbutting the helmetless Walker.

You can see another angle of the headbutt below:

The Colts entered the game averaging 3.7 penalties per game, which was the fewest in the NFL. They had back-to-back penalties on that drive that helped set up a Titans field goal. The referees must have missed the headbutt, because such a move should result in an ejection.